@Meddler: What are your thoughts on built-in gold generating mechanics?

With Ashe no longer among the group of Champions who have built-in gold generation mechanics, we're now down to only . Bonus income can be a considerable advantage in the right hands, but in TF's and GP's cases, they're forced to give up actual combat power due to how they innately make more money than their opponents. Draven, on the other hand, has to actually land a Champion kill to cash in, but the result is much more powerful.

I'd like to take the gold generation thing a step further by developing a Champion who not only has a gold-generation mechanic, but also gains combat benefits from how much gold has been generated via said mechanic.

Here is an example excerpted from one of my Champion Concepts. Don't judge the numbers; judge the concept.

P - Pickpocket
Whenever Severa damages an enemy Champion with an ability, she places an Easy Prey mark on it for 4 seconds. Whenever she lands a basic attack or Hoodwink on an enemy marked by Easy Prey, she consumes the mark, gaining 10 bonus gold and 20/30/40% bonus movement speed for 1 second (increases at levels 7 and 13, respectively).

Additionally, whenever an enemy Champion dies within 4 seconds of Severa dealing damage to them, she gains 25 bonus gold.

R - The Finishing Touch Passive: Severa's basic attacks deal bonus physical damage equal to 3/4/5% of all gold she has obtained via Pickpocket. (This does not count as bonus attack damage, and is unaffected by critical strikes.)

(There's also an active component to Severa's ultimate, but that's not important to this topic.)

Numbers aside, what are your thoughts on mechanics like this?